The floral repressors TEMPRANILLO1 and 2 modulate salt tolerance by regulating hormonal components and photo-protection in Arabidopsis.

Members of the plant specific RAV family of transcription factors regulate several developmental and physiological processes. In the model plant Arabidopsis thaliana, the RAV TEMPRANILLO 1 (TEM1) and TEM2 control important phase changes such as the juvenile to adult and the vegetative to reproductive transitions. Besides their known regulatory function in plant development, a transcriptomics analysis of transgenic plants overexpressing TEM1 also revealed overrepresentation of Gene Ontology (GO) categories related to abiotic stress responses. Therefore, to investigate the biological relevance of these TEM-dependent transcriptomic changes and elucidate whether TEMs contribute to the modulation of plant growth in response to salinity, we analyzed the behavior of TEM gain and loss of function mutants subjected to mild and high salt stresses at different development stages. With respect to increasing salinity, TEM overexpressing plants were hypersensitive whereas the tem1 tem2 double mutants were more tolerant. Precisely, tem1 tem2 mutants germinated and flowered faster than the wild-type plants under salt stress conditions. Also, tem1 tem2 plants showed a delay in salt-induced leaf senescence, possibly as a consequence of downregulation of jasmonic acid biosynthesis genes. Besides a shorter life cycle and delayed senescence, tem1 tem2 mutants appeared to be better suited to withstand oxidative stress as they accumulated higher levels of α-tocopherol (an important antioxidant metabolite) and displayed a slower degradation of photosynthetic pigments. Taken together, our studies suggest novel and crucial roles for TEM in adaptive growth as they modulate plant development in response to environmental changes such as increasing soil salinity.

Characterization of inflammatory response in hepatorenal syndrome: Relationship with kidney outcome and survival.

BACKGROUND: Several lines of evidence indicate that decompensated cirrhosis is characterized by the presence of systemic inflammation. Hepatorenal syndrome (HRS-AKI) is a unique type of renal failure that occurs at late stages of cirrhosis. However, confirmation of the presence and significance of such inflammatory response in HRS-AKI is lacking. AIM AND METHODS: To characterize the systemic inflammatory response, as estimated by measuring a large number of cytokines, in 161 patients hospitalized for an acute decompensation of cirrhosis: 44 patients without acute kidney injury (AKI), 63 patients with hypovolaemia-induced AKI and 58 patients with HRS-AKI. RESULTS: HRS-AKI was characterized by an altered cytokine profile compared to the other two groups, particularly IL-6, IL-8, TNF-α, VCAM-1, fractalkine and MIP-1α. The inflammatory response was not related to presence of bacterial infection, concomitant acute-on-chronic liver failure or severity of renal dysfunction. Patients who responded to terlipressin and albumin had only a decrease in TNF-α and RANTES after treatment without changes in other cytokines. Interestingly, patients with persistent HRS-AKI had higher levels of IP-10 and VCAM-1 compared to those with resolution of HRS-AKI. VCAM-1 was also an independent predictor of 3-month mortality. A systems biology analysis approach showed that the inflammatory status of HRS-AKI was similar to that of chronic nonhepatic inflammatory conditions, such as lupus erythematosus or inflammatory bowel disease. CONCLUSION: Hepatorenal syndrome is characterized by a marked systemic inflammatory state, reminiscent of that of nonhepatic inflammatory diseases, that correlates with patient outcomes.

Photoperiod Control of Plant Growth: Flowering Time Genes Beyond Flowering.

Fluctuations in environmental conditions greatly influence life on earth. Plants, as sessile organisms, have developed molecular mechanisms to adapt their development to changes in daylength, or photoperiod. One of the first plant features that comes to mind as affected by the duration of the day is flowering time; we all bring up a clear image of spring blossom. However, for many plants flowering happens at other times of the year, and many other developmental aspects are also affected by changes in daylength, which range from hypocotyl elongation in Arabidopsis thaliana to tuberization in potato or autumn growth cessation in trees. Strikingly, many of the processes affected by photoperiod employ similar gene networks to respond to changes in the length of light/dark cycles. In this review, we have focused on developmental processes affected by photoperiod that share similar genes and gene regulatory networks.

Extracellular Vesicles From Liver Progenitor Cells Downregulates Fibroblast Metabolic Activity and Increase the Expression of Immune-Response Related Molecules.

Extracellular vesicles (EVs) mediate cell-to-cell crosstalk whose content can induce changes in acceptor cells and their microenvironment. MLP29 cells are mouse liver progenitor cells that release EVs loaded with signaling cues that could affect cell fate. In the current work, we incubated 3T3-L1 mouse fibroblasts with MLP29-derived EVs, and then analyzed changes by proteomics and transcriptomics. Results showed a general downregulation of protein and transcript expression related to proliferative and metabolic routes dependent on TGF-beta. We also observed an increase in the ERBB2 interacting protein (ERBIN) and Cxcl2, together with an induction of ribosome biogenesis and interferon-related response molecules, suggesting the activation of immune system signaling.

The molecular genealogy of sequential overlapping inversions implies both homologous chromosomes of a heterokaryotype in an inversion origin.

Cytological and molecular studies have revealed that inversion chromosomal polymorphism is widespread across taxa and that inversions are among the most common structural changes fixed between species. Two major mechanisms have been proposed for the origin of inversions considering that breaks occur at either repetitive or non-homologous sequences. While inversions originating through the first mechanism might have a multiple origin, those originating through the latter mechanism would have a unique origin. Variation at regions flanking inversion breakpoints can be informative on the origin and history of inversions given the reduced recombination in heterokaryotypes. Here, we have analyzed nucleotide variation at a fragment flanking the most centromere-proximal shared breakpoint of several sequential overlapping inversions of the E chromosome of Drosophila subobscura -inversions E1, E2, E9 and E3. The molecular genealogy inferred from variation at this shared fragment does not exhibit the branching pattern expected according to the sequential origin of inversions. The detected discordance between the molecular and cytological genealogies has led us to consider a novel possibility for the origin of an inversion, and more specifically that one of these inversions originated on a heterokaryotype for chromosomal arrangements. Based on this premise, we propose three new models for inversions origin.

An easy route to the massive karyotyping of complex chromosomal arrangements in Drosophila.

Inversion polymorphism is widespread in the Drosophila genus as well as in other dipteran genera. The presence of polytene chromosomes in some insect organs and, thus, the possibility to observe the different arrangements generated by inversions through a microscope enhanced the cytological study of this structural polymorphism. In several Drosophila species, these studies provided evidence for the adaptive character of this polymorphism, which together with the standing interest to uncover targets of natural selection has led to a renewed interest for inversion polymorphism. Our recent molecular characterization of the breakpoint regions of five inversions of the E chromosome of D. subobscura has allowed us to design a PCR-based strategy to molecularly identify the different chromosomal arrangements and, most importantly, to determine the E chromosome karyotype of medium- and large-sized samples from natural populations. Individuals of a test sample that were both cytologically and molecularly karyotyped were used to establish the strategy that was subsequently applied to karyotype a larger sample. Our strategy has proved to be robust and time efficient, and it lays therefore the groundwork for future studies of the E chromosome structural polymorphism through space and time, and of its putative contribution to adaptation.